Over the past 15 years as a member of the Maternal Fetal Medicine Unit (MFMU) network, the UNC MFMU has completed 14 studies and has three currently in progress. We are seventh overall in recruiting among all sites, and are ranked number seven in retention/completion. UNC excels at Hispanic recruitment; overall about 27% of our participants are Hispanic. Our proven record of performance coupled with our large, diverse base of potential study participants and our knowledge of clinical trials and observational studies will enable us to continue our substantive contribution to the quality and quantity of research in the MFMU Network. We have assembled a talented and committed team of physicians, fellows, graduate students, research nurses, clinical research assistants, laboratory staff, and other investigators in our Perinatal Research Core, an alliance of investigators dedicated to understanding and improving pregnancy outcomes through state-of-the- art research. UNC Health Care serves as the lead organization with two other health systems, Wake Health and Hospitals in Raleigh, NC, and the Greenville Health System in Greenville, SC included as satellite sites. With the addition of the Greenville Health System in this application, we had more than 22,000 births across sites, of which 20 - 25% are considered high-risk because of maternal co-morbidities, including substance abuse, fetal anomalies, pregnancy complications, or preterm birth risk profile, including multiple gestations. Together, these three health care systems bring more than 30 years of productive multi-site research, experienced investigators, state-of-the-art care facilities, a stable population, conversion to a common electronic medical record system (Epic), and a commitment to excellence in collaborative research to continued membership in the MFMU. Specific aims of this proposal are to: 1) contribute to the development of evidence-based practices in the field of maternal-fetal medicine, 2) work collaboratively with other sites in the investigation of problems in clinical obstetrics, particularly those related to low birth weight, prematurity, and medical problems of pregnancy, and 3) bring our strong interdisciplinary approach to and extensive experience in conducting observational studies in perinatal medicine to the network. Our internal goals for the coming cycle include expanding our reach within the WakeMed Health and Hospitals system; successfully integrating a new satellite location in Greenville, South Carolina; improving our rankings in all areas to be in the top half of the network; and establishing internal standards for conducting chart abstraction.